Silver halide element containing an organic semiconductor

ABSTRACT

The amine salts of linear polyaniline compounds, including substituted polyaniline compounds, are useful, semiconductors. These materials are generally soluble in popular organic solvents and have resistivities between 10 -   3  and 10 9  ohm-cm. These compounds are useful in the formation of semiconductor compositions, including self-supporting films, and various semiconductor elements such as antistatic films and fibers.

This is a continuation-in-part application based on Ser. No. 212,640,filed Dec. 27, 1971, and Ser. No. 455,705, filed Mar. 28, 1974 both ofwhich are now abandoned.

This invention relates to new organic semiconductors and to compositionsand elements containing these materials.

The usefulness of semiconducting organic materials is often associatedwith a combination of desirable properties, e.g., (1) electronicproperties such as low electrical resistivity, (2) chemical propertieslike low reactivity and (3) physical properties which facilitateconvenient preparation of useful articles of manufacture. A number ofinorganic materials well known in the art, such as metals (e.g., silver,copper) or semiconductors (e.g., germanium, silicon) have usefulelectrical properties. However, because it is possible to introduce andmodify their physical and chemical properties such as solubility,melting point, etc., by relatively minor changes in the chemicalstructure of the organic molecules, organic semiconductors have adistinct advantage over inorganic materials. As a result, organicsemiconductors can be tailor-made to display multiple useful propertiesnot found in inorganic substances.

The preparation of organic materials showing appreciable electricalconductivity has been the subject of several publications and reviews[(see, for example, Y. Okamoto and W. Brenner, "Organic Semiconductors",Reinhold Publishing Corp., New York (1964); F. Gutmann and L. F. Lyons,"Organic Semiconductors", John Wiley and Sons, Inc., New York (1967);and J. E. Katon, "Organic Semiconducting Polymers", Marcel Dekker, Inc.,New York (1968)]. They may be classified in four broad groups:

1. Non-complex organic semiconductors, consisting of single monomericspecies. (The term "semiconductor" as used herein described electricallyconducting materials with a resistivity in the range of 10.sup.⁻³ to 10⁹ohm-cm).

2. Complex organic semiconductors, consisting in general of at least twomonomeric species (comprising an electron donor moiety and an electronacceptor moiety, respectively) associated to a certain extent throughcharge transfer.

3. Non-complex polymeric organic semiconductors.

4. Complex organic semiconductors where at least one of the electrondonor moieties or the electron acceptor moieties is attached to, or partof, a polymeric chain.

Most of the known organic semiconductors, showing resistivity valueslower than 10⁴ ohm-cm, belong to the second and fourth categories, butmany of these are unstable under ambient conditions, hence reducingtheir usefulness considerably. Furthermore, those which show reasonablestability are usually obtained in the form of insoluble, infusiblepowders, which, in general, are not amenable to fabrication into usefularticles of manufacture.

In recent publications [e.g., Y. Matsunaga, J. Chem. Phys. 42, 2248(1965) and Y. Okamoto, S. Shah, and Y. Matsunaga, J. Chem. Phys., 43,1904 (1965)] new organic semiconductors of low resistivity have beendescribed in which a sulfur-containing polycyclic hydrocarbon(tetrathiotetracene) acts as the electron donor in dative-type chargetransfer complexes with any one of three organic acceptors: o-chloranil,o-bromanil or tetracyanoethylene. (The term "dative-type charge transfercomplex" describes a charge transfer complex between an electron donorand an electron acceptor in which the constituents are in an ionizedform in the ground state of the complex. These complexes may also bedesignated by the term "ion-radical salts", the electron donor becomingthe "cation-radical" and the acceptor becoming the "anion-radical".) Thedescribed complexes, however, lack solubility in organic solvents aswell as in water. Likewise, tetrathiotetracene itself, although showingone of the lower electrical resistivities of the non-complex organicsemiconductors reported (resistivity of the compressed powder is of theorder of 10⁴ ohm-cm), is only very slightly soluble at room temperaturein a few very strong organic solvents. None of the aforementionedorganic semiconductors has sufficient solubility to permit readyfabrication of coatings, films, fibers, etc, utilizing such materials.

It is, therefore, an object of this invention to provide a novel classof organic semiconductors.

It is a further object to provide compositions containing the novelorganic semiconductors described herein and processes for preparing suchcompositions.

It is still a further object of this invention to provide elementscontaining the novel organic semiconductors and semiconductorcompositions described herein.

These and other objects and advantages are accomplished using certainamine salts of linear polyaniline and substituted linear polyanilinecompounds, which salts are useful semiconductors. These amine salts areformed by the interaction of certain organic amines (i.e. organiccompounds containing primary amine, secondary amine and tertiary aminegroups, as well as compounds containing groups derived from aminegroups, such as imine groups) with suitable inorganic or organic acids.The starting amines are typically insulators or at best, lowconductivity semiconductors. The resultant amine salts are, however,highly conducting semiconductors. The resistivity of the presentmaterials is in the range of 10.sup.⁻³ to 10⁹ ohm-cm and issubstantially independent of humidity.

Although, in general, salts formed by the action of an organic amine andan acid are known in the art, most of these materials are notsemiconductors. For example, such amine salts as Rosanilinehydrochloride, Malachite Green, Pararosaniline hydrochloride, Auramine Oand Methylene Violet all exhibit insulating properties (i.e.,resistivity values >10⁹ ohm-cm) when tested in a vacuum and in theabsence of moisture. L. T. Yu et al., Compt Rend, 260, 5026 (1965),reported high conductivity for emeraldine sulfate when it containedexcess sulfuric acid and/or water. However, the material was amicrocrystalline powder insoluble in useful solvents and hence, lackingutility as a constituent of practical conducting coatings. Additionalpublications by Dr. Yen and others that discuss such insoluble andhumidity dependent polyaniline semiconductors as emeraldine sulfate areCompt Rend. 258, 6421 (1964); Compt Rend, 262, 459, (1966); RevueGenerale de Electricite, 9, 1014 (1966); Journal of Polymer Science:Part C, 16, 2931 and 2943 (1967); Electrochemica Acta, 13, 1451 (1968);Compt Rend, 269, 964 (1969 ); Journal of Polymer Science, 22, 1187(1969); and Journal Chem. Phys, 68, 1055 (1971).

The present state of the art does not broadly assist one in predictingsemiconductive properties of organic solids merely from structuralconsiderations. However, I have found a specific class of organic aminesalts which not only have good semiconductive properties substantiallyindependent of humidity, but which are stable and which are sufficientlysoluble in solvents including typical organic solvents to form eitheralone or in combination with a co-dissolvable binder material, liquidsolutions that are substantially optically clear and which do notscatter light between 400 nm and 700 nm. Such solutions can be preparedconveniently, thereby facilitating the ready formation of stablesemiconductor compositions and elements.

The organic semiconductors useful in this invention are described by thefollowing expression:

    I.   D[A].sub.q

wherein:

D is a moiety which can be represented by the structure: ##SPC1##

in which:

J represents either R₁ or a group having the formula ##SPC2##

K represents either R₃ or a group having the formula ##SPC3##

R₁ and R₄ may be the same or different, and are selected from the groupsconsisting of hydrogen; hydroxy; lower alkyl having from 1 to about 8carbon atoms such as methyl, ethyl, isopropyl, butyl, etc; lower alkoxyhaving from 1 to about 8 carbon atoms in the alkyl moiety such asmethoxy, ethoxy, propoxy, butoxy, etc; amino, including substitutedamino radicals such as alkyl- and dialkylamino radicals having from 1 toabout 8 carbon atoms in each alkyl moiety and acylamino radicals such asacetylamino, benzoylamino, naphthoylamino, etc; aryl such as phenyl,naphthyl, including substituted aryl radicals such as tolyl, acyl suchas acetyl, benzoyl, naphthoyl, etc; thio, nitrate; carboxylate;sulfonate; halogen; and cyano radicals;

R₂ and R₃ each represent (1) an uncharged (i.e., non-ionized) radicalselected from an oxo radical (=0); an imino radical (=NH) includingalkyl-substituted imino radicals having from 1 to about 8 carbon atomsin the alkyl substituent, aryl-substituted imino radicals such asphenylimino, naphthylimino and acyl-substituted imino radicals such asacetylimino, benzoylimino; and a thioxo radical (=S) or (2) a charged(i.e., ionized) radical selected from an alkoxonium radical (=OR, whereR is alkyl) having from 1 to about 8 carbon atoms in the alkyl moiety;an iminium radical (=NH₂) including alkyl- and dialkyl-substitutediminium radicals having from 1 to about 8 carbon atoms in each alkylmoiety; and a sulfonium radical (=SH);

n and p are each integers having the following combinations of values:

    when J represents                                                             and K represents R.sub.3,                                                                          p = 0                                                                              n = 0, 1, 2, 3, 4, 5                                                     p = 1                                                                              n = 0, 1, 2, 3                                                           p = 2                                                                              n = 0, 1                                            when J represents R.sub.1 and                                                 K represents R.sub.3,                                                                              p = 0                                                                              n = 0, 1, 2, 3, 4, 5, 6                                                  p = 1                                                                              n = 0, 1, 2, 3, 4                                                        p = 2                                                                              n = 0, 1, 2                                                              p = 3                                                                              n = 0                                               when J represents R.sub.1 and                                                 K represents         p = 0                                                                              n = 0, 1, 2, 3, 4, 5                                                     p = 1                                                                              n = 0, 1, 2, 3                                                           p = 2                                                                              n = 0, 1;                                       

A is a monomeric or polymeric moiety such that when R₂ and R₃ are eachan uncharged radical, A is an acid and when R₂ and/or R₃ is a chargedradical, A is an anion derived from an acid.

In any semiconductor described herein, however, the value of q for eachD will not be greater than the number of amine groups included withinthe D moiety. Stated in summary, q is a positive integral number that isgreater than 0 and less than or equal to the number of amine groups inthe D moiety. It will be understood that the term amine group hereinmeans and refers to primary, secondary and tertiary amine groups as wellas groups derived from amine groups, such as imine groups.

Based on optical examination and knowledge of their semiconductingproperties, it is believed that the amine salt semiconductors of thisinvention have, as is the case with crystalline materials, an orderedconfiguration of units (e.g. moieties as represented by D and A).Referring to Table II below it should be emphasized that in any sampleof the semiconductors described herein wherein a plurality ofsemiconductor molecules (i.e. as represented by the foregoing formulas)are present, and hence a plurality of D moieties, the averageassociation of A moieties with D moieties can be nonstoichiometricwithin the range described for q. As a result, analysis of a sample forassociation between A and D moieties can indicate that the average valueof q is a positive, integral or non integral number of from greater thanzero to less than or equal to the number of amine groups in the largestD moiety present in the sample under analysis.

A particularly useful group of linear moieties having 2 to 5 rings isrepresented by the formula II above wherein a, m, n, p, x and y have thefollowing combinations of values:

    a = 0, m = 1, x = 1, y = 0                                                                    p = 0      n = 0, 1, 2, 3                                     a = 1, m = 0, x = 1, y = 0                                                                    p = 0      n = 0, 1, 2                                                        p = 1      n = 0, 1                                           a = 1, m = 0, x = 0, y = 1                                                                    p = 0      n = 0, 1, 2                                                        p = 1      n = 0                                          

It should be emphasized that, for those semiconductors represented byformula II, and described in the preceding paragraph, it was extremelyunexpected and not predictable that they would exhibit both desirablesolubility in organic solvents and useful conductivity. The shorterchain lengths, although they might enhance solubility, would alsodecrease total conjugation and restrict electron delocalization to adegree thought perhaps insufficient for the occurrence of conductivitywithin the range set forth herein.

It should be noted that both terminal groups shown on the right handportion of formula II are divalent radicals and only one is present at atime. For simplicity, these divalent radicals are shown as beingattached with a solid and a broken line.

Moieties represented by Formula II above can be derived from a broadvariety of organic amines. In general, such amines are not in thecompletely reduced or leuco form and contain at least one quinoid ringrepresented by the structure: ##SPC4##

Although there can be more than one quinoid ring in the amine portion ofthe salt, the number of quinoid rings in the D moiety will not in anycase exceed by more than one, one-half of the total number of rings.Presence of quinoid ring structures gives rise to conjugation betweenrings in the structure and is thought to provide electron delocalizationthat is desirable in organic semiconductor compounds. Formula II aboveis thus merely a convenient way of representing the compounds of theinvention and is not meant to indicate which rings are always aromaticand which are of the quinoid type. Although particular rings are notnecessarily always aromatic or always quinoidal, there is alwayspara-coupling of all anilino, substituted anilino, quinoid, orsubstituted quinoid moieties contained within the instant compounds.

Of course, any of the para-coupled rings of the amine portion can besubstituted at the ortho- or meta-positions of the ring. Suitablesubstituents would include a hydroxy radical; an alkyl radical,including substituted alkyl radicals having from 1 to about 6 carbonatoms such as methyl, ethyl, isopropyl, tert-butyl, etc; an alkoxyradical including substituted alkoxy radicals having from 1 to about 6carbon atoms in the alkyl moiety; an acyl radical, including substitutedacyl radicals; an aryl radical, including substituted aryl radicals,such as phenyl, tolyl, naphthyl, etc; and other radicals such as aroxyl,sulfo, carboxyl, amino, including alkylamino and arylamino, nitro, ahalogen radical, cyano, etc.

Within the broad range of acids useful in preparing amine salt compoundsdescribed herein, one can select an acid that will provide or enhancesolubility of the resultant amine salt semiconductor in a solvent ofchoice. Preferably, the amine salt semiconductors described herein haveorganic solvent solubility, i.e., form a substantially optically clearliquid organic solvent solution that does not scatter visible light.Although the particular acid will affect electrical properties of theamine salt, there are so many acids that one skilled in the art andhaving an understanding of this invention can select an acid thatprovides both desired solubility and desired conductivity. It isextremely desirable that such a tailoring of solubility and conductivitycan be accomplished.

It should be emphasized also that, in cases where the A moiety ispolymeric (derived from a polymeric acid) the amine salt semiconductoris a very advantageous polymer that conducts electricity within therange specified herein. Although there are known electrically conductingpolymers, such as the TCNQ charge transfer compounds described in U.S.Pat. No. 3,162,641, polymers of the type described herein are highlysoluble in popular solvents, chemically stable at high humidity anddesirably electrically conductive even under extremely low humidity(e.g., at high altitude, under vacuum and under other low humidityenvironments).

In general, the compounds of this invention are prepared by theinteraction of a suitable amine with a monomeric or polymeric acid.Mixtures of compatible amines and acids can be used, if desired. Theparent amine compound is suitably oxidized to an oxidation state higherthan the leuco or lowest oxidation state. The oxidized amine is theninteracted with an acidic compound in a solvent such as an ether (e.g.,tetrahydrofuran, ethyl ether, isopropyl ether, etc), a ketone (e.g.,acetone, etc,), and alcohol (e.g., methanol, ethanol, n-propanol,isopropanol, etc), an aromatic solvent (e.g., benzene, toluene, etc), orwater, or in mixtures of these or other solvents. When the resultingamine salt has substantial solubility in the solvent or solvent mixtureemployed, isolation of the solid is accomplished by using concentrationswhich exceed the solubility limit of the amine salt in the solvent orsolvent mixture of choice. The precipitate is then filtered and washed.Procedures of this type are described, for example, by A. G. Green etal, J. Chem. Soc., 97, 2392 (1910), R. Willstatter et al., Chem. Ber.,40, 2677 (1907).

Amines useful in preparing the present semiconductor compounds accordingto such representative procedures include the illustrative compounds setforth in Table I.

TABLE I

1. n-(p-anilinophenyl)-1,4-benzoquinone imine

2. N-[p-(4-anilino)anilinophenyl]-1,4-benzoquinone imine

N-(p-anilinophenyl)-N'-(p-aminophenyl)-1,4-benzoquinone diimine

N-[p-(1,4-benzoquinone diimino)phenyl]-N'-phenyl-1,4-benzoquinonediimine

N-[p-(4-aminoanilino)phenyl]-N'-(p-aminophenyl-1,4-benzoquinone diimine

6.N-{p-[4-(p-anilino)anilino]anilinophenyl}-N'-p-[N-(p-aminophenyl)-1,4-benzoquinonediimino]-phenyl-1,4-benzoquinone diimine

7. N-(p-dimethylamino)phenyl-1,4-benzoquinone diimine

8. N-[p-(1,4-benzoquinone diimino)phenyl]-1,4-benzoquinone diimine

9. N,N'-diphenyl-1,4-benzoquinone diimine

10. N-[p-(4-aminoanilino)phenyl]-1,4-benzoquinone imine

11. N-[p-(4-hydroxyanilino)phenyl]-1,4-benzoquinone imine

12. N-{p-[4-(1,4-benzoquinone imino)anilino]phenyl}-1,4-benzoquinoneimine

13. N-[p-(4-dimethylaminoanilino)phenyl]-1,4-benzoquinone imine

14. N-[p-(4-anilino)anilinophenyl]-N'-acetyl-1,4-benzoquinone diimine

15. N-{p-[4-(p-methoxyanilino)anilino]phenyl}-1,4-benzoquinone imine

16. N-(p-anilinophenyl)-N'-[p-(4-aminoanilino)phenyl]-1,4-benzoquinonediimine

17. N-(p-anilinophenyl)-N'-[p-(1,4-benzoquinoneimino)-phenyl]-1,4-benzoquinone diimine

The following are representative of the numerous acids which can be usedto prepare the present semiconductor compounds. Useful inorganic acidswould include such materials as haloid acids, e.g., hydrogen chloride,hydrogen bromide, hydrogen fluoride, hydrogen iodide, fluoboric acid,etc; sulfur acids such as sulfurous acid, sulfuric acid, thiosulfuricacid, thiocyanic acid, etc; acids of phosphorous such as phosphorousacid, phosphoric acid, etc; nitrogen acids such as nitrous acid, nitricacid, etc; and the like. Useful organic acids would include variousmono-, di- and polyfunctional organic acids such as aliphatic acids,both saturated and unsaturated having from 1 to about 8 carbon atoms,for example, formic, acetic, propionic, maleic, fumaric, butynedioic,oxalic, succinic, adipic acid, acetylene-dicarboxylic acid; aromaticacids such as phthalic, terephthalic, benzoic, toluic, p-toluenesulfonicacid, naphthoic acid; and organic compounds containing acidic hydrogenatoms such as barbituric acid and 2-thiobarbituric acid. In addition tothe monomeric inorganic and organic acids described above, variousacidic polymers can be used. Any polymer containing an acidic function,such as carboxy or sulfo, or containing a sufficiently acidic hydrogenatom, as in certain polyhydroxy substituents, would be useful inproviding semiconducting polymers according to this invention. Usefulpolymers would include vinyl polymers containing acid functionality, forexample: (a) poly(acid) polymers such as poly(acrylic acid),poly(methacrylic acid), etc; (b) copolymers of esters and acids such aspoly(methyl methacrylate-methacrylic acid), poly(butylmethacrylate-methacrylic acid), poly(vinyl acetate-maleic acid), etc;(c) copolymers of an ether and acid or anhydride such as poly(vinylmethyl ether-maleic anhydride), etc; (d) copolymers of olefin and acidsuch as poly(ethylene-maleic acid), etc: (e) other copolymers (includingterpolymers and quaterpolymers, etc) containing acidic functionality asdescribed above; (f) polymers containing the sulfo groups such assulfonated poly(styrene), etc; (g) copolymers, terpolymersquaterpolymers, etc, containing the sulfo group, etc. Classes ofpolymers other than vinyl polymers, such as natural resins, cellulosics,polycondensates, silicones, alkyd resins, polyamides, etc, would also beuseful provided they contain acid functionality imparted by the presenceof carboxy or sulfo groups or by the presence of acidic hydrogen atoms.Particularly useful polymers are poly(acrylic acid) andpoly(ethylene-maleic acid).

The moiety A can also be provided partially or totally by the metal saltderived of an acid, e.g., zinc chloride. For example, a semiconductingamine salt has been prepared in which the moiety A as indicated byelemental analysis comprises 1/2 mole of zinc chloride in conjunctionwith 31/2 moles of hydrochloric acid. The conductivity of this compoundis substantially independent of relative humidity, and the salt iselectrically conductive in high vacuum.

Particular useful amine salt semiconductor compounds include thoseformed from one of sulfuric acid, hydrobromic acid, fluoboric acid,benzoic acid or p-toluene sulfonic acid together with one ofN-{p-[4-(p-methoxy anilino)anilino]phenyl}-1,4-benzoquinone imine,N-[p-(1,4-benzoquinone diimino)phenyl]-N'-phenyl-1,4-benzoquinonediimine, N-(p-anilinophenyl)-N'-(p-aminophenyl)-1,4-benzoquinonediimine, and N-[p-(4-anilino)-anilinophenyl]-1,4-benzoquinone imine.Other especially useful semiconductors include polymeric amine saltssuch as N-(p-anilinophenyl)-N'-(p-aminophenyl)-1,4-benzoquinone andn-(p-anilinophenyl)-n'-(p-aminophenyl)-1,4-benzoquinone.

The amine salt semiconductor compounds described herein can be used toprepare useful semiconductor compositions. Such compositions can includeat least one of thepresent semiconductor compounds in combination with,i.e., in the presence of, at least one binder material. In one aspect,the semiconductor compositions of this together can have a semiconductorand a binder togther in a liquid solution, such as an organic solventsolution. The compositions can be prepared conveniently by dispersing ordissolving one or more semiconductors in a liquid solution of bindermaterial.

It will be appreciated that, for photographic purposes and the like,substantially optically clear solutions that can be coated to formlayers that do not scatter visible light (e.g. from 400 to 700 nm) arepreferred. For other purposes, solutions not having optical clarity ordispersions are suitable.

Preferred binders are generally film-forming polymeric materials.Typical such polymers include

I. Natural resins including gelatin, cellulose ester derivatives such asalkyl esters of carboxylated cellulose, hydroxy ethyl cellulose, carboxymethyl cellulose, carboxy methyl hydroxy ethyl cellulose, etc;

II. Vinyl resins including

a. polyvinyl esters such as a vinyl acetate resin, a copolymer of vinylacetate and crotonic acid, a copolymer of vinyl acetate with an ester ofvinyl alcohol and a higher aliphatic carboxylic acid such as lauric acidor stearic acid, polyvinyl stearate, a copolymer of vinyl acetate andmaleic acid, a poly(vinylhaloarylate) such aspoly(vinyl-m-bromobenzoate), a terpolymer of vinyl butyral with vinylalcohol and vinyl acetate, a terpolymer of vinyl formal with vinylalcohol and vinyl acetate, etc;

b. vinyl chloride and vinylidene chloride polymers such as a poly(vinylchloride), a copolymer of vinyl chloride and vinyl isobutyl ether, acopolymer of vinylidene chloride and acrylonitrile, a terpolymer ofvinyl chloride, vinyl acetate and vinyl alcohol, poly(vinylidenechloride) a terpolymer of vinyl chloride, vinyl acetate and maleicanhydride, a copolymer of vinyl chloride and vinyl acetate, etc;

c. styrene polymers such as a polystyrene, a nitrated polystyrene, acopolymer of styrene and monoisobutyl maleate, a copolymer of styrenewith methacrylic acid, a copolymer of styrene and butadiene, a copolymerof dimethylitaconate and styrene, polymethylstyrene, etc;

d. methacrylic acid ester polymers such as a poly(alkylmethacrylate),etc;

e. polyolefins such as chlorinated polyethylene, chlorinatedpolypropylene, etc;

f. poly(vinyl acetals) such as a poly(vinyl butyral), etc; and

g. poly(vinyl alcohol);

III. Polycondensates including

a. a -hydroxyphenyl)propane; of 1,3-disulfobenzene and2,2-bis-(4-hydoxyphenyl)propane;

b. a polyester of diphenyl-p,p'-disulfonic acid and2,2-bis(4-hydroxyphenyl)propane;

c. a polyester of 4,4'-dicarboxyphenyl ether and2,2-bis(4-hydroxyphenyl)propane;

d. a polyester of 2,2-bis(4-hydroxyphenyl)propane and fumaric acid;

e. pentaerythrite phthalate;

f. resinous terpene polybasic acid;

g. a polyester of phosphoric acid and hydroquinone;

h. polyphosphites;

i. polyester of neopentylglycol and isophthalic acid;

j. polycarbonates including polythiocarbonates such as the polycarbonateof 2,2-bis(4-hydroxyphenyl)propane;

k. polyester of isophthalic acid,2,2-bis-4-(β-hydroxyethoxy)phenylpropane and ethylene glycol;

l. polyester of terephthalic acid, 2,2-bis-4-(β-hydroxyethoxy)phenyl andethylene glycol;

m. polyester of ethylene glycol, neopentyl glycol, terephthalic acid andisophthalic acid;

n. polyamides;

o. ketone resins; and

p. phenolformaldehyde resins;

IV. Silcone resins; and

V. Alkyd resins including styrene-alkyd resins, silicone-alkyd resins,soya-alkyd resins, etc.

Solvents of choice for preparing semiconductor compositions of thepresent invention can include a number of solvents preferably organicsolvents such as alcohols including aliphatic alcohols preferably having1 to 8 carbon atoms including methanol, ethanol, propanol, isopropanol,etc, aromatic alcohols, polyhydric alcohols, substituted alcohols,including 2-methoxyethanol, ketones including aliphatic ketones such asacetone, 2-butanone, methyl isobutyl ketone, etc, aromatic ketonesincluding cyclohexanone, etc, chlorinated solvents including aliphaticchlorinated solvents such as methylene chloride, ethylene chloride,propylene chloride, etc, organic carboxylic acid having 1 to 10 carbonatoms such as formic, acetic, propionic, etc, substituted carboxylicacids, including esters derived from organic carboxylic acids having 1to 10 carbon atoms such as methyl acetate, ethyl acetate, etc, lowerdialkylsulfoxides such as dimethylsulfoxide, dimethylformamide,acetonitrile, and water. Also included are mixtures of these solventsamong themselves or with other organic solvents.

In preparing the compositions useful results are obtained where thesemiconductor is present in an amount equal to at least about 1 weightpercent of the total composition. The upper limit in the amount ofsemiconductor present can be widely varied in accordance with usualpractice. In those cases where a binder is employed, it is normallyrequired that the semiconductor be present in an amount from about 1weight percent of the coating to about 99 weight percent of the coating.A preferred weight range for the semiconductor in binder containingcompositions is from about 10 weight percent to about 60 weight percent.

Semiconductor elements, i.e., element having an amine salt semiconductorin combination with a support can be prepared, for example, by applyinga semiconductor or semiconductor composition on a supporting substrate.In one embodiment, the semiconductor elements can include a supporthaving thereon a coated layer that includes a semiconductor as describedherein and, optionally, a binder. Suitable supports which are alsoconventionally termed supporting substrates, are broadly variable andthe choice in any instance will depend on the intended application.Polymeric films, such as those useful in photography, as well as glass,paper (including papers coated with water resistant resins) and metalsare representative of desirable support materials, It is emphasized,also, that support geometry is not limited, and will vary depending onthe intended use for the element. Fibers, including synthetic polymerfibers useful for weaving into cloth, can constitute supportingsubstrates for semiconductor elements. Also, spheres or othergeometrical configurations can be useful supports and can be made up ofany material that is chemically and physically compatible with thesemiconductor compositions. In this regard, a support can carry asubbing layer to promote adhesion of the semiconductor composition.

When coating a semiconductor composition on a support, the thickness ofthe layer can be controlled if desired, by using such techniques asdoctor blade coating or extrusion hopper coating. Generally, a wetcoating thickness of about 0.0001 inch to about 0.01 inch is preferable,with a wet coating thickness of about 0.0002 inch to about 0.001 inchusually being most preferable. Useful results can be obtained outside ofthis range and layers including the semiconductor might be eitherthicker or thinner, for example if spray coating, fluidized bed coating,dip coating or other coating techniques are used. Evaporation of thecoating solvent, optionally accelerated by drying under an environmentof controlled temperature and/or humidity, produces a durable layer inwhich the semiconductor is contained. Although not intending to be boundby theory, it is believed that the semiconductor is present in the layeras a dispersion of microcrystals, even if initially dissolved in thecoating solution.

It should be emphasized that, in instances where the support will acceptand retain amine salt semiconductor, whether by absorption, imbibition,or otherwise, semiconductor elements werein a support has thereon abinderless semiconductor layer can be prepared by treating such asupport material with a solution of the semiconductor. Alternatively,the semiconductor layer can be formed in situ on the semiconductorelement, using various techniques. For example, a coating compositioncontaining either an amine or an acid useful in preparing an amine saltsemiconductor, and optionally a binder material, can be applied to asupport and dried. Thereafter, the treated support can be treated withthe component not included in the coating composition. Typically, thistreatment will use a liquid solution or vapors of the active component.Normal care would be taken to insure that the treatment did not imparethe integritiy of the previously coated layer. In one preferredembodiment, a polymeric acid can be coated from a solvent, optionallywith additional binder material, to prepare a layer that is subsequentlyovercoated with a solution of an amine (compounds including primaryamine, secondary amine and tertiary amine groups as well as compoundsincluding groups derived from amines, such as imine groups).

In situations where either the binder used in a semiconductorcomposition or a polymeric amine salt as described herein have asufficient film-forming capability, the composition can be formed as aself-supporting solid or plastic film. In such cases, a separate supportis not required, and the resulting continuous film is a semiconductingmaterial. Some such self-supporting films can be prepared using coatingtechniques such as those described herein. Generally, the coating wouldbe applied to a nonadherent surface and then physically stripped fromthe surface after evaporation of the solvent from the coatingcomposition. In other instances, it may be desirable to prepare asemiconductor composition (or coating composition(s) containing theamine and/or acid) that can be extruded to produce a self-supportingsemiconductor composition) as a film or filament, in the case of fibers.

In certain applications, it may be desirable to have a semiconductorelement include a protective layer, usually adjacent to thesemiconductor. Such protective layers may be used for a variety ofreasons, for example to protect the semiconductor, which may be in aseparate layer, from abrasion or attack by solvents or other chemicals.Alternatively, the protective layer may be used to protect thesemiconductor and/or other constituents in the element from undesiredchemical or electronic interaction, such as by preventing electricalconduction or diffusion of the semiconductor and/or other constituentsbetween various regions of the element. The protective layer is usuallya film forming polymer that can be applied using coating techniques suchas those described elsewhere herein. Desirable materials includepolymers or copolymers of vinylidene chloride including copolymerscontaining substantial amounts of vinylidene chloride with acrylicmonomers such as acrylonitrile, methyl acrylate, and the like. Suchpreferred polymers are described in U.S. Pat. Nos. 2,627,088, 2,491,023,2,779,684, 3,437,484, 3,271,345, 3,143,421, 2,943,937 and 2,999,782.However, other suitable resins for making the protective layer areresins of cellulose acetate, cellulose acetate-butyrate, cellulosenitrate, polyvinyl butyral, polymethyl methacrylate, polyvinyl chloride,polystyrene, polyesters, polycarbonates, and the like. In certainsituations, it may be desirable to have the protective layer beelectrically insulating or substantially optically transparent, or both.Preferred materials, if this is the case, can easily be determined.

Semiconductor elements as described herein can be used either as, or in,a variety of articles of manufacture. Importantly, semiconductorcompositions in the form of self-supporting, conducting films orsemiconductor elements in which an electrically insulating support iscoated with an amine salt semiconductor can be used in electronicscomponents such as resistors, capacitors, rectifiers, transistors, etc.Also, such compositions and elements can be used as an antistaticsupport material for magnetic recording tapes.

In another aspect, semiconductor compositions and elements in which thesemiconductor layer and the support (or self-supporting conducting film)are not more than about 0.5 optical density between about 400 to 800 nm.are particularly useful when substantially optically transparentconducting materials are desired. Such materials can be used as staticinhibiting photographic film support, as conducting windows inelectronic instruments, as anti-static camera lenses or the like.

When semiconductor compositions and elements as described herein areextruded or otherwise formed as filaments, electrically conductingfibers are prepared. Using such fibers permits weaving fabric thatresists generating static electricity on frictional contact.Alternatively, a filamentary semiconductor composition or element can beused as a core and overcoated with other materials (e.g. polymers) toprepare composite conducting fibers suitable for weaving into cloth.

Semiconductor elements as described herein can be coated withlight-sensitive materials to prepare semiconductor elements that arealso image-forming elements. In one aspect, a semiconductor elementhaving thereon a layer comprising an amine salt semiconductor can becoated with a silver halide photographic emulsion of the type used torecord electron beam radiation. Desirably, the semiconductor layer andsilver halide layer are contiguous to each other, and either can becontiguous to the support. As may be desirable with many types ofphotographic elements, the support may carry a subbing layer to improveadhesion of subsequently coated layers. Protective layers as describedherein can be included as interlayers or overcoats, if desired. Othersilver halide emulsions can be applied to semiconductor compositions orelements, as by the coating techniques described previously, to preparelight-sensitive photographic elements that inhibit the formation ofstatic electricity. It may be desirable to interpose an electricallyinsulating layer between the semiconductor and the silver halide. Thiscan be accomplished by having a semiconductor and silver halide coatedon opposite sides of an electrically insulating support or byinterposing an electrically insulating layer, usually a clear polymer,between the two if the silver halide is coated on a conducting surfaceof the semiconductor composition or element. It will be appreciatedthat, for optimal photographic use, the support and any protective (e.g.insulating) layers may preferably be clear, i.e., substantiallyoptically transparent. If the back (non-emulsion) surface of the silverhalide coated semiconductor element bears the semiconductor, and if inwinding the element on itself or positioning several elements in a frontto back relationship this surface may contact the silver halide, then itmay be desirable to overcoat the semiconductor with a protective layerof polymeric or other insulating material. This, of course, could alsoserve as an abrasion resistant layer.

In still another embodiment, semiconductor elements of this inventioncan be coated with an organic or inorganic photoconductive material toprepare electrophotographic elements. The photoconductor is usuallyapplied contiguous to a conducting surface of the semiconductor element.However, electrically insulating protective layers, preferably thin, canbe coated either under the semiconductor and the photoconductor, betweenthe two or over both.

Another use for the present amine salt semiconductors is in preparingconducting particles useful as toners in electrophotographicdevelopment. Generally, such toners are fine powders that have anelectrically insulating core bearing a low resistance outer shell. Suchtoners are described, for example, in patents such as U.S. Pat. Nos.2,976,144 and 3,099,041. By using core constituents as the support andovercoating such support with an amine salt semiconductor orsemiconductor composition, according to techniques described herein,useful conducting toners can be prepared. Conducting toners aregenerally desirable when induction toning techniques are used to developan electrostatic image.

Other embodiments are also useful. For example, when the photoconductorcomposition is amenable to fabrication by molding techniques,electrically conducting molded articles can be prepared.

The following examples are included for a further understanding of theinvention.

EXAMPLE 1

The amine 3 of Table I is prepared by the method of A. G. Green et al(supra). A solution containing 0.5 g. of this amine in 250 ml. of etheris filtered into a stirred solution containing 1.2 g. of maleic acid in100 ml. of ether. A blue-green precipitate forms and is separated byfiltration, washed with 50 ml. of ether and dried at room temperature.The volume resistivity of the material, measured as a compressed powder,is 140 ohm-cm. Elemental analysis indicates that the product isbasically a dimaleate salt of the free amine.

EXAMPLE 2

A solution is prepared containing 0.3 g. of the amine of Example 1 and200 ml. of ether. This solution is filtered into a solution containing2.5 ml. of dichloroacetic acid dissolved in 50 ml. of ether. Ablud-green precipitate forms and is separated by filtration, washed witha solution containing 3 ml. of dichloroacetic acid in 80 ml. of ether,and dried at room temperature. The volume resistivity of thedichloroacetate salt of the amine, measured as a compressed powder, is8500 ohm-cm.

EXAMPLE 3

A solution is prepared containing 0.05 g. of the amine of Example 1 and50 ml. of ether. This solution is filtered into a solution containing anexcess of trifluoroacetic acid in 50 ml. of ether. An olive-greenprecipitate is formed and separated by filtration, followed by washingwith 70 ml. of ether, and drying at room temperature. The volumeresistivity of the trifluoroacetate salt of the amine, measured as acompressed powder, is 7800 ohm-cm.

EXAMPLE 4

A solution is prepared containing 0.05 g. of the amine of Example 1 and50 ml. of ether. This solution is filered into a second solutioncontaining 0.03 g. of phthalic acid and 50 ml. of ether. A dark greenprecipitate is formed and separated by filtration, followed by washingwith 70 ml. of ether and drying at room temperature. The volumeresistivity of the phthalate salt of the amine, measured as a compressedpowder, is 3.5 × 10⁴ ohm-cm.

EXAMPLE 5

A solution is prepared containing 0.05 g. of the maleate amine salt ofExample 1, 1.0 ml. of a 2% solution of poly(vinyl acetate) in methanol,and 40 ml. of methanol with stirring for 5 minutes. The solution isfiltered and coated on polyethylene terephthalate film support and driedat room temperature. The surface resistivity of the coating is measuredin air by applying painted graphite electrodes on the surface of thefilm and measuring the resistance with an electrometer. The term"surface" or "thin film" resistivity denotes the electrical resistanceof a square of a thin film of material, measured in the plane of thematerial between opposite sides. For films which obey Ohm's law, this isan intrinsic property of the film. If the resistance is measured inohms, the thin film or surface resistivity is expressed as ohms persquare. (R. E. Aitchison, Aust. J. Appl. Sci., 5 10 (1954). Theresistivity of the coating is 4.1 × 10⁷ ohm/square, and this value issubstantially unchanged when measured in high vacuum.

EXAMPLE 6

The dihydrobromide salt of amine 4 of Table I is prepared using themethod of Willstatter et al (supra p. 2682), but using hydrobromic acidinstead of hydrochloric acid and using acetone instead of a mixture ofethanol and chloroform. A solution is prepared containing 0.05 g. ofthis salt, 1.0 ml. of a 2% solution of poly(vinyl acetate) in methanol,and 25 ml. of methanol with stirring for 5 minutes. The solution isfiltered and coated on polyethylene terephthalate film support. Thecoating is dried at room temperature, cured for 3 minutes at 100°C, andthe surface resistivity of the coating is measured and found to be 2.2 ×10⁸ ohm/square.

EXAMPLE 7

A solution is prepared containing 0.08 g. of the amine salt formed bythe reaction of hydrobromic acid with the amine 3 of Table I, 5 ml. of a2% solution of poly(vinyl acetate) in methanol, and 15 ml. of methanolby stirring for 5 minutes. The filtered solution is coated onto apoly(ethylene terephthalate) film support, dried at room temperature andthe surface resistivity of the coating measured for resistivity which isfound to be 6.3 × 10⁹ ohm/square.

EXAMPLE 8

A solution is prepared containing 0.05 g. of the amine salt formed bythe reaction of sulfuric acid with the amine 2 of Table I, 1.0 ml. of a2% solution of poly(vinyl acetate) in methanol, and 30 ml. of methanolwith stirring for 5 minutes followed by filtering. The filtered solutionis coated on poly(ethylene terephthalate) film support, dried at roomtemperature and cured for 3 minutes at 120°C. The surface resistivity ofthe coating, measured as in Example 5 is 2.4 × 10⁷ ohm/square.

EXAMPLE 9

A solution is prepared by stirring 0.05 g. of the amine salt formed bythe reaction of hydrochloric acid with the amine 5 of Table I, and 9.5ml. of methanol for 10 minutes. Then 0.5 ml. of a 2% solution ofpoly(vinyl acetate) in acetone is added with stirring followed byfiltering. The filtered solution is coated on poly(ethyleneterephthalate) film support and dried at room temperature. Surfaceresistivity of the coating is 4.3 × 10⁷ ohm/square. After overnightexposure to high vacuum, the resistivity is 1.1 × 10⁷ ohm/square whenmeasured in high vacuum.

EXAMPLE 10

A solution is prepared containing 0.20 g. of the amine salt formed bythe reaction of p-toluenesulfonic acid with the amine 15 of Table I in amixed solvent containing 16 ml. of methanol, 14 ml. of ethanol, 0.8 ml.of n-butanol, and 0.14 g. of poly(vinyl butyral), by stirring for 75minutes. The filtered solution is coated on poly(ethylene terephthalate)film support and dried at room temperature. The surface resistivity ofthe coating is 1.8 × 10⁸ ohm/square.

EXAMPLE 11

When the object is to prepare a semiconductor element coating, it isoften advantageous to prepare the semiconductive composition byincluding the amine and the acid in appropriate amounts in the coatingsolution. This eliminates the need to isolate the semiconducting aminesalt prior to preparing the coating solution. This process isillustrated by the following example. In a solution containing 25.4 ml.of ethanol and 11.0 ml. of methanol, 0.22 g. of poly(vinyl butyral) isdissolved. To this solution is added 0.18 g. of the amine 15 of Table Iand 10.6 ml. of a 1% solution (w/vol) of maleic acid in absoluteethanol, and the mixture is stirred for 20 minutes. The filteredsolution is coated on poly(ethylene terephthalate) film support, driedat room temperature, and cured for 45 seconds at 100°C. The surfaceresistivity of the coating is 1.0 × 10⁹ ohm/square.

EXAMPLE 12

Emeraldine is prepared, purified, and isolated as the hydrochlorideusing the techniques described generally by R. Willstatter (supra). Acoating solution is prepared by stirring 0.05 g. of emeraldinehydrochloride in 20 ml. of methanol for 10 minutes, then adding 1.0 ml.of a 2% solution of alcohol-soluble cellulose acetate butyrate polymerin methanol containing 6.5% n-propanol. The solution is filtered, coatedby pouring a small amount of polyester film support and dried at roomtemperature. The resultant coating has a surface resistivity of 8.3 ×10⁸ ohm/square when measured as in the preceding examples. Afterexposure to a high vacuum overnight, the coating has a resistivity of1.9 × 10⁹ ohm/square when measured in a high vacuum.

EXAMPLE 13

A solution is prepared containing 0.04 g of the amine salt formed by thereaction of hydrobromic acid with the amine 2 of Table I and 0.06 g ofpoly(vinyl formal) in a mixed solvent containing 9.3 ml of methanol, 6.4ml of 1,2-dichloroethane, and 3.0 ml of 2-methoxyethanol, by stirringfor 1 hour. The filtered solution is coated on poly(ethyleneterephthalate) film support, dried at room temperature and cured for 45seconds at 100°C. The resulting clear coating has a surface resistivityof 4.4 × 10⁶ ohm/square. The conducting coating is subsequentlyovercoated with a protective layer of a terpolymer of vinylidenechloride, methyl acrylate and itaconic acid, applied from a 2.5%solution (w/vol) in methyl isobutyl ketone. The surface resistivity ofthe resulting two-layer coated system is 1.4 × 10⁷ ohm/square.

EXAMPLE 14

A solution is prepared containing 0.20 g of the amine salt of Example 13and 0.12 g of poly(vinyl formal) in a solvent mixture containing 42 mlof ethanol, 16.2 ml of 1,2-dichloropropane, 9.8 ml of1,1,2-trichloroethane, and 7.2 ml of 2-methoxyethanol. The filteredsolution is coated on cellulose acetate film support, dried at 35°C, andcured for 45 seconds at 100°C. The conducting coating, is thenovercoated with a layer of clear polymer comprising a terpolymer ofmethyl acrylate, vinylidene chloride and itaconic acid from a 2.5%solution (w/vol) in methyl isobutyl ketone. This layer is dried at roomtemperature and cured for 1.5 min at 60°C. The resistivity of thetwo-layer coated system is 2.8 × 10⁸ ohm/square. A gelatin sub and agelatino-silver halide photographic emulsion are then coated in sequenceabove the layer of clear polymer to provide a static-free photographicelement. The multilayer photographic element shows satisfactorysensitometric properties, thus demonstrating the efficacy of the clearpolymer layer in preventing unwanted changes in the light sensitivity ofthe emulsion resulting from any action of constituents of the conductinglayer.

EXAMPLE 15

A solution is prepared containing 0.60 g of the amine 2 of Table I and0.48 g of poly(vinyl formal) in a mixed solvent comprising 145 ml ofethanol, 64 ml of 1,2-dichloropropane, 40 ml of 1,1,2-trichloroethane,and 29 ml of 2-methoxy ethanol. To this solution is added 23 ml of anethanol solution containing 1 g of aqueous hydrobromic acid (48 %) in 59ml of ethanol. The filtered solution is coated on cellulose acetate filmsupport, dried at 50°C, and cured for 40 seconds at 100°C. The resultingconducting coating is overcoated with a layer of clear polymer from a 5%solution (w/vol) of poly(methyl methacrylate) in 1,2-dichloropropane.This layer is also dried at 50°C and cured at 100°C. The two-layercoated element has a resistivity of 2 × 10⁹ ohm/square, which isunchanged when the coated element is subjected to typicalblack-and-white or color film processing sequences commonly used inphotography. The two-layer element shows excellent antistatic propertiesin conjunction with a gelatino-silver halide photographic emulsioncoated on the opposite side of the film support. In addition, thetwo-layer coated element produces no adverse effects when pressed inintimate contact with a typical photographic emulsion. The two-layercoated element also shows good abrasion resistance and adhesion of thecoated layers. These tests establish the effectiveness of the two-layercoated element as a permanent, antistatic backing for photographicfilms. The photographic emulsion may also be coated on the same side ofthe film support as the two-layer coated element, as in Example 14.

EXAMPLE 16

A solution is prepared containing 0.113 g of the amine salt of Example13 1.85 ml of a 5% solution (w/vol) of a copolymer of methylmethacrylate and methacrylic acid in methanol, 12.6 ml of methanol and0.6 ml of 2-methoxyethanol, by stirring for 45 minutes. The filteredsolution is coated on poly(ethylene terephthalate) film support, driedat 50°C, and cured for 45 seconds at 60°C. The surface resistivity ofthe coating is 3.2 × 10⁶ ohm/square. A layer of clear polymer is thenapplied above the conducting layer, comprising a terpolymer ofacrylonitrile, vinylidene chloride and acrylic acid coated from a 2.5%solution (w/vol) in methyl isobutyl ketone. This layer is dried at 47°Cand cured for 1.5 min at 100°C. A photoconductive layer, comprising anorganic photoconductor in a polycarbonate binder, is coated above thebarrier layer using chlorinated solvents. This layer has a wet thicknessof 0.004 inch, is dried for 3 minutes at 52° C, and cured at 95°C for 3minutes. The resistivity of the conducting layer in the three-layersandwich is 6.3 × 10⁷ ohm/square. It serves as an effective conductivelayer in an electrophotographic element comprising a photoconductivelayer, a conductive layer and an insulating support.

EXAMPLE 17

A coating of the amine salt formed by the reaction of hydrobromic acidwith the amine 5 of Table I is prepared on a poly(ethyleneterephthalate) film support as in Example 9. The surface resistivity ismeasured as in Example 5 and found to be 1.5 × 10⁷ ohm/square at roomtemperature. Measured in a high vacuum, the surface resistivity is 1.7 ×10⁷ ohm/square. A potential of 47 volts d.c. is applied to a strip ofthe coating by making contact through graphite electrodes painted on thesurface leaving an uncoated area approximately 1.9 × 1.9 cm. squarebetween the electrodes. Direct current is allowed to flow continuouslyfor 7 days while the high vacuum is maintained (pressure <1 × 10.sup.⁻⁵mm Hg). At the end of this time, the resistivity of the coating is 2.0 ×10⁷ ohm/square. From the geometry and physical properties of thecoating, it is calculated that the total electric charge (1.53 coulombs)which has passed through the coating is 320 times greater than thatwhich could be carried by all the ions under one electrode. This isconclusive evidence that the conductivity is at least 99.7% due to themigration of electrons and/or positive holes and not due to ionicmigration.

This behavior of a typical coating containing an organic semiconductorof the type described in this invention contrasts markedly with that ofthe usual amine salts or quaternary ammonium salts in which conduction,if it occurs at all, is by the motion of ions in the presence ofabsorbed moisture. In such cases, a decrease in the moisture content (byreducing the relative humidity of the air) produces a substantialdecrease in the conductivity, and at low relative humidity, or in a highvacuum, such materials do not have useful electrically conductiveproperties and would be classified as insulators.

EXAMPLE 18

The following compounds are prepared in a manner similar to thatpreviously described and measured for volume resistivity as inExample 1. The results obtained are shown in Table II below.

                                      Table II                                    __________________________________________________________________________    Structure and Resistivity of Typical Semiconducting Amine Salts               Desig-                                                  Resistivity           nation                                                                             Amine Salt                                         ohm-cm                __________________________________________________________________________    I                                                        320                  II                                                       420                  III                                                      260                  IV                                                      1,800                 V                                                       3,600                 VI                                                      1,500                 VII                                                                                                                                   2,900                 __________________________________________________________________________

EXAMPLE 19

A solution of 0.5 g. of amine 3 of Table I in 50 ml. of acetone is addedwith stirring to a solution of 0.5 g. of a 1:1 copolymer of ethylene andmaleic acid dissolved in a solvent mixture containing 30 ml. of acetoneand 20 ml. of methanol. To the resulting dark green solution, 300 ml. ofethyl ether is added to precipitate the polymeric amine salt. The solidsalt is removed from the solution by filtration and dried in vacuum. Thevolume resistivity of the material, measured as a compressed powder, is2 × 10⁶ ohm-cm.

EXAMPLE 20

The reaction mixture of Example 19 containing the dissolved polymericsemiconducting amine salt, is alternately coated onto a poly(ethyleneterephthalate) film support, without isolating the solid semiconductor,and the coating is dried. The resultant coating has a surfaceresistivity of 1.8 × 10¹⁰ ohm-square when measured as in Example 5.After exposure to a high vacuum overnight, the coating has a resistivityof 1.9 × 10¹⁰ ohm square when measured in high vacuum.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

I claim:
 1. A semiconductor element comprising a support having thereona silver halide emulsion layer and a layer comprising a semiconductorcomposition comprising a binder and a semiconductor having organicsolvent solubility and represented by the expression:

    D[A].sub.q

wherein: D represents a moiety having the structure: ##SPC5## in which:J represents either R₁ or a group having the formula ##SPC6## Krepresents either R₃ or a group having the formula ##SPC7## R₁ and R₄are each selected from the group consisting of a hydrogen atom, ahydroxy radical, a lower alkyl radical, a lower alkoxy radical, an aminoradical, an aryl radical, an acyl radical, a carboxylate radical, a thioradical, a nitrate radical, a sulfonate radical, a halogen atom and acyano radical; R₂ and R₃ each represent (1) an uncharged radicalselected from the group consisting of oxo, imino and thioxo radicals or(2) a charged radical selected from the group consisting of alkoxonium,iminium, and sulfonium, radicals; and n and p are each integers havingthe following combinations of values:

    when J                                                                        represents                                                                    and K represents R.sub.3,                                                                       p = 0   n = 0, 1, 2, 3, 4, 5                                                  p = 1   n = 0, 1, 2, 3                                                        p = 2   n = 0, 1                                            when J represents R.sub.1 and                                                 K represents R.sub.3,                                                                           p = 0   n = 0, 1, 2, 3, 4, 5, 6                                               p = 1   n = 0, 1, 2, 3, 4                                                     p = 2   n = 0, 1, 2                                                           p = 3   n = 0                                               when J represents R.sub.1 and                                                 K represents      p = 0   n = 0, 1, 2, 3, 4, 5                                                  p = 1   n = 0, 1, 2, 3                                                        p = 2   n = 0, 1;                                       

A is an acid when R₂ and R₃ are each an uncharged radical and when R₂and/or R₃ is a charged radical, A is an anion derived from an acid; andq represents the number of A moieties associated with each D and is apositive integer that is greater than 0 and less than or equal to thenumber of amine groups in the D moiety.
 2. A semiconductor element asdescribed in claim 1, wherein A is selected from the group consisting ofan inorganic acid, an organic acid and an acidic polymer.
 3. Asemiconductor element as described in claim 1, wherein the semiconductoris an amine salt of a member selected from sulfuric acid, hydrobromicacid, fluoboric acid, benzoic acid p-toluic acid or p-toluenesulfonicacid together with a member selected from the group consisting ofN-{p-[4-(p-methoxy anilino) anilino] phenyl}-1,4-benzoquinone imine,N-[p-(1,4-benzoquinone diimino) phenyl]-N'-phenyl-1,4-benzoquinonediimine, N-(p-anilinophenyl)-N'-(p-aminophenyl)-1,4-benzoquinonediimine, and N-[p-(4-anilino)-anilinophenyl]-1,4-benzoquinone imine. 4.A semiconductor element as described in claim 1, wherein the silverhalide emulsion and semiconductor composition are on opposite sides ofthe support.
 5. A semiconductor element as described in claim 4 whereina protective layer is over the semiconductor composition.
 6. Asemiconductor element as described in claim 5 wherein the protectivelayer comprises poly(methyl methacrylate).
 7. A semiconductor element asdescribed in claim 1, wherein the silver halide emulsion andsemiconductor composition are on the same side of the support, and havea protective layer between the silver halide and the semiconductorcomposition.
 8. A semiconductor element as described in claim 7, whereinthe protective layer comprises poly(methyl methacrylate).
 9. Asemiconductor element comprising a support having thereon a silverhalide emulsion layer and a layer comprising a semiconductor compositioncomprising a binder and a semiconductor having organic solventsolubility and represented by the expression:

    D[A].sub.q

wherein: D represents a moiety having the structure: ##SPC8## in which:J represents either R₁ or a group having the formula ##SPC9## Krepresents either R₃ or a group having the formula ##SPC10## R₁ and R₄are each selected from the group consisting of a hydrogen atom, ahydroxy radical, a lower alkyl radical, a lower alkoxy radical, an aminoradical, an aryl radical, an acyl radical, a carboxylate radical, a thioradical, a nitrate radical, a sulfonate radical, a halogen atom and acyano radical; R₂ and R₃ each represent (1) and uncharged radicalselected from the group consisting of oxo, imino and thioxo radicals or(2) a charged radical selected from the group consisting of alkoxonium,iminium, and sulfonium radicals; and n and p are each integers havingthe following combinations of values:

    when J represents                                                             and K represents R.sub.3,                                                                           p = 0   n = 0, 1, 2, 3                                  when J represents R.sub.1 and                                                 K represents R.sub.3, p = 0   n = 0, 1, 2                                                           p = 1   n = 0, 1                                        when J represents R.sub.1 and                                                 K represents          p = 0   n = 0, 1, 2                                                           p = 1   n = 0;                                      

A is an acid when R₂ and R₃ are each an uncharged radical and when R₂and/or R₃ is a charged radical, A is an anion derived from an acid; andq represents the number of A moieties associated with each D and is apositive integer that is greater than 0 and less than or equal to thenumber of amine groups in the D moiety.